1. Technical Field
The present invention relates to an image forming apparatus which forms an image by discharging a liquid on a medium.
2. Related Art
In the related art, as this type of image forming apparatus, an apparatus which detects the thickness of paper in such a way that an optical readout apparatus, such as a Charge-Coupled Device (CCD) camera or an artificial retina chip, is installed on one side of a paper feeding mechanism and one side face of the paper is optically read out by the optical readout apparatus (for example, refer to JP-A-2003-292196), and an apparatus which includes a gap sensor for converting the movement of a paper roller in the vertical direction into an electrical signal, and detects the thickness of the paper in response to a signal detected by the gap sensor when the paper is fastened by the paper roller (for example, refer to JP-A-2007-260991) have been proposed.
However, since each of the above-described apparatuses requires that a dedicated sensor be installed in order to detect the thickness of the paper, there is a problem in that a new area is necessary for the installation, such that the apparatus increases in size and is disadvantageous in terms of cost.